有限体积法在三维非稳态铝合金挤压过程模拟中的应用

研究基于Euler网格的有限体积法(Finite volume method,FVM)模拟三维大变形非稳态铝型材挤压过程的基本理论和关键技术,应用C语言编制程序求解速度场、温度场等物理场量,并利用运动界面追踪技术--流体体积(Volume of fluid,VOF)方法捕捉材料流动前沿.采用"移动的网格"处理计算区域边界的移动问题,实现对真实物理过程的数值模拟,并将模拟结果与比较成熟的商品化有限元软件DEFORM-3D的模拟结果进行对比,表明所建立的有限体积法模拟模型有效、可靠.结果对比表明,FvM模型的模拟结果更符合实际,证明有限体积法比有限元法更适合大变形挤压过程模拟.

APPLICATION OF FINITE VOLUME METHOD INTO SIMULATION OF TRANSIENT FLOW OF THREE-DIMENTIONAL ALIMINIUM EXTRUSION

Three-dimensional non-steady aluminum profile extrusion processes with large deformations are simulated using finite volume method (FVM) based on Euler mesh. The key technologies are studied and the simulation program is coded using C langrage to obtain the fields such as velocity field and temperature field. Volume of fluid (VOF) method is used to capture the free surface of the material. The "moving grids system" is introduced to treat the moving problem of the boundaries of the calculated area caused by the moving of the extrusion ram. The numerical simulation of real physical processes is realized. The simulation results for an aluminum profile extrusion process with a L-shaped cross-section obtained by the finite volume mathematic model agree with the results simulated by Deform-3D. And the results of finite volume mathematic model are much closer to the practical ones. The effectiveness and exactness of the finite volume model established are proved. The finite volume model is more suitable to the materials forming process simulation with a large or severe deformation, such as aluminum profile extrusion process, than finite element model.